Certain graduates of a class are donating money to place an ad in a booklet celebrating s school’s centennial. Their names will be placed in the ad. The intent of the ad (and sale of the booklet) is to raise money for the school. We have a choice between a one page ad and a two page “centerfold” ad. Some members of this group (and I) believe that the two page ad is somewhat ostentatious and belies the intent of the donation.

My problem is to communicate to the rest of the group using diplomatic language that the two page ad tends to be ostentatious. Is there a better word or phrase for “somewhat ostentatious”? Dictionary.com gives several synonyms – none of which seem to fit a convincing yet diplomatic statement.

I often favor the word overwrought when I'm trying to be as diplomatic as possible about ostentatious language. Unfortunately, it is an uncommon word and your using it, ironically, might trigger the reaction you're trying to avoid if it seems that you are trying to speak "above" them. If you think they are comfortable with that level of vocabulary, you might use "overwrought." As in, "Don't you think the ad a bit...what's that word...overwrought?"

overwrought (comparative more overwrought, superlative most overwrought, adj.)
1. in a state of excessive nervousness, excitement, or anger; Extremely tense, anxious, or upset; filled with emotion, emotional; uneasy2. elaborate; overdone

Ostentatious sounds about as diplomatic as you can get in this situation while still making your point. How about avoiding the need for a specific word at all: "An ad of that size seems inconsistent with our fund-raising objectives."

@HaL's 'excessive' and @Mitch's 'too much' or 'overdoing it' are probably the best.

Going with the full two-page ad could be described as excessively 'self-congratulatory', but that's not a synonym.

It also appears to be a bit needy, in the sense of 'wanting or needing affection, attention, or reassurance, especially to an excessive degree.'

Borderline narcissistic is pseudo-clinical, and probably not diplomatic.

Saying that it appears slightly egocentric would be diplomatic in some circles.

On the other hand, people who donate money often like to be recognized, or in fact donate money in order to be recognized. So it's hard for me to come up with a term that is too critical, given the nature of the enterprise.